Trying to understand microstakes blind defence. Been looking at 6max range charts and I find many that show a very narrow range of hands one should defend with and some that show a very wide range. I assume this is because of the odds your getting. I would like to understand the theory behind each as memorizing charts is not my strong suite.

any advice appreciated.

maybe one is for the small blind and one is for the big blind? or you are looking at charts that show entirely different action by the time it gets to you?

it heavily depends on the villain that raises.
also if its a 2x or 3x or 2.5x raise, the smaller, the wider we can defend

you must learn the ranges for 2.5x open raise, then you automatically adjust by size, is important to know the range vs one size, then your brain will easy adapt without learning all situations. the same i use for defending vs different position, for example defending vs mp, means defend vs utg + some hands, and so on

Maybe refer to ranges such as those at gtowizard and run some sims for pre and flop etc and you will be able to get a grasp of what flops are good for hero in particular.

Also maybe get a sub at a training site - runitone has some content ref blind defence

There are a few fundamental reasons for the differences in the charts, but all the reasons have the same cause: they are based on certain assumptions that the chart creator makes.

For example, some charts are based on a single person's database. If my opponents usually open wide against me, my database will reflect that fact and prompt me to create charts with wider defend ranges. Other charts are based on large player groups but in specific pools, such as several hundred microstakes cash game players on Pokerstars, or perhaps on 300 MTT players on ACR. These differences affect the results.

Chart creators have different assumptions about their readers' skill levels post flop: if the chart is for very new or very weak players, the charts will show a tighter defense range because the users are less capable of realizing their equity post flop. If the chart is for strong aggressive players who can outplay their opponents post flop out of position, the ranges will be wider.

As a general principle, you should realize that you will lose the most money from the blinds. The reason is simple: when you play out of position, you will find it hard to realize your equity with strong hands and to bluff with weak ones. You can significantly simplify your game by defending a tight range in the blinds. You will give up some preflop equity, but you will avoid more difficult (and potentially costly) postflop situations.

^ good posting

I think the best thing is to play thousand of hands. By playing many hands you can have an idea about your opponents ranges based on thousands of showdowns

Some of the issue might be that there is no one “if someone raises my big blind, should I call chart”, but rather multiple such charts. The position of the open raiser is critical for construction of a bb defense range. It should be easy to see why. A UTG raiser generally has a significantly tighter opening range than a button raiser. You should be adjusting your defense range accordingly, much tighter vs the UTG raiser and rather wide vs the button raiser, and widest of all of the SB is the open raiser — in this case not only will the opening range be very wide, but you also will be in position post flop.

Now at micros, some of this is a bit different, especially if those at your table are not really paying much attention to position. At such tables you probably want to widen your defense range against early position opens and tighten it against late position opens. If you see UTG players opening hands like ATo (a perfectly reasonable open for a mid to late position, but bad for UTG) it makes no sense to play a tight defense range. If they are not opening more marginal holdings from the button, your more marginal defense hands no longer are profitable.

It is important to keep in mind that most of these decisions are marginal ones where errors either way are not going to be hugely impactful to your EV. While I understand the desire to play a theoretically correct strategy (especially if your goal is to move up in stakes) often a slightly non optimal but simpler strategy will work out better than a difficult but theoretically correct one.